KR102556168B1 - Protective film for window glass in which cross-section of glass is curved in three dimensions, method for manufacturing the same, and photocurable adhesive composition therefor - Google Patents

Abstract

The present invention acts as a support film, and the outer layer 300 made of a heat-deformable synthetic resin film; anti-fingerprint reinforcement layer 200; an anti-curl layer 400; stress relieving layer 500; UV curable deformable adhesive layer 600; And peeling layers (100 and 700); provides a protective film for 3D window glass, a method for manufacturing the same, and a photocurable adhesive composition for the same.
According to the present invention, a protective film for 3D window glass having excellent heat resistance and adhesion and preventing or reducing strain and surface lifting, a manufacturing method thereof, and a photocurable adhesive composition for the same are provided, and process efficiency and economy are high.

Description

Protective film for window glass having a three-dimensionally curved cross section, method for manufacturing the same, and photocurable adhesive composition for the same

The present invention relates to a protective film for 3D window glass having properties of a deformable material and an adhesive at the same time, a manufacturing method thereof, and a photocurable adhesive composition therefor.

A display cover window (hereinafter abbreviated as a window) is a component that protects the display panel screen from external influences.

With the development of mobile phones with liquid crystal displays, windows were made of transparent plastic. However, with the development of smartphones, physical input devices such as keyboards disappeared due to the introduction of screen touch functions. As a result, the size of displays also increased.

Recently, smartphone design innovation has continued centering on the display. Glass windows have evolved from a flat glass plate (2D) to a 2.5D window with gently curved edges or a curved 3D window such as the Galaxy Edge series (see Fig. 1).

In addition, with the advent of foldable displays that can be flexibly bent, bent, or even folded, flexible polyimide (PI) materials rather than glass are used as windows. Colorless Polyimide (CPI), a plastic material, makes the flexible Polyimide (PI) material, which has been used as a substrate for flexible display panels, transparent and has improved hardness and durability.

As the cross-section of such a window develops into 2D, 2.5D and 3D, a protective film for protecting the surface of the window has also been developed by changing adhesive strength, shape, and/or configuration.

In the method of simply increasing the adhesive strength of the protective film, it is difficult to remove the protective film when replacing it for reasons such as incorrect attachment or damage, and the edge of the protective film is attached in a curved shape, but the force to return to the original flat shape continues to act, causing a lifting phenomenon.

In Patent Document 1 (Korean Patent Publication No. 10-1221441, published on January 11, 2013) and Patent Document 2 (Korean Registered Patent Publication No. 10-1580502, published on December 31, 2015), the case where the protective film is manufactured according to the curved shape (2.5D or 3D shape) of the cross section of the window is disclosed, but the curved shape The edge of the film is damaged by external force or continuous friction during daily life, or the adhesive strength is lowered and the phenomenon still occurs. In addition, since the protective film having a curved edge is manufactured in such a way that the thickness becomes thinner toward the edge, the protective film must be separately manufactured according to the size of the window, and it is difficult to uniformly cut the curved edge. It is difficult to apply to a 3D window having a curved shape.

In general, a protective film for a 2D window having a flat cross-section has a basic configuration including a hard coating layer for external protection and adhesive for adhesion to window glass on a base layer such as PET having a resilience because it has a stiff property. On the other hand, a protective film for a 2.5D or 3D window having a curved cross section has been developed that includes a UV curable variable layer that can change its shape according to the curved shape of the window under the substrate layer.

For example, in Patent Document 3 (Korean Patent Registration No. 10-1697049, published on January 16, 2017), a protective film for mobile devices having a self-bending function having a layer configuration of hard coating layer-base layer-molding layer-adhesive layer-release film is disclosed. In the above document, the molding layer includes an acrylic resin having a glass transition temperature below room temperature and a photoreactive oligomer capable of being cured by ultraviolet rays, and thus may be molded to match the curved 3D display surface by a curing reaction.

The protective film of the above document can impart some degree of adhesion to the curved portion of the window, but contraction and expansion of the film occur due to heat generated by the use of a smartphone, which causes lifting on the window surface or the restoring force of the base layer. There is a possibility that stress is transmitted to the molding layer and deformation occurs.

In Patent Document 4 (Republic of Korea Patent Publication No. 10-2018-0106668, published on October 1, 2018), in order to solve the problems appearing in Patent Document 1, a release layer-reinforced protective layer-outer skin layer-deformable material layer-inner skin layer-adhesive layer-an electronic device protective film having a layer configuration of a release layer is disclosed. In the above document, the deformable material layer (corresponding to the molding layer) is installed below the outer skin layer (corresponding to the base layer), and can be molded to match the curved 3D display surface by a curing reaction, and the inner skin layer is deformable. It is installed to prevent peeling between the material layer and the adhesive layer.

However, since the protective film of the above literature has a high storage modulus (G′) of PET constituting the outer skin layer, it is still difficult to prevent stress deformation, and as a result, the adhesive strength may be lowered and the window surface may be lifted.

In this situation, there has been a need to develop a new protective film for 3D window glass that has high heat resistance and can prevent or reduce strain during heat generation, reverse curl prevention, and surface lifting.

Republic of Korea Patent Registration No. 10-1221441 (published on January 11, 2013) Republic of Korea Patent Registration No. 10-1580502 (Announced on December 31, 2015) Republic of Korea Patent Registration No. 10-1697049 (published on January 16, 2017) Republic of Korea Patent Publication No. 10-2018-0106668 (published on October 1, 2018)

An object of the present invention is to provide a protective film for 3D window glass that has excellent heat resistance and adhesive strength while preventing or reducing stress deformation during heat generation, reverse curl prevention, and surface lifting, and a new material for the same.

In addition, an object of the present invention is to provide a protective film for 3D window glass having properties of a deformable material and an adhesive at the same time, and a photocurable adhesive composition therefor.

In addition, an object of the present invention is to provide a method for manufacturing a protective film for 3D window glass that well implements a 3D shape and uniformly manufactures a protective film for 3D window glass with a micro thickness over a large area that is adhered for a long period of time.

The problem to be solved by the present invention is not limited to the above-mentioned problem (s), and another problem (s) not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the present invention,

an outer skin layer 300 acting as a support film and made of a heat-deformable synthetic resin film;

An anti-fingerprint reinforcement layer 200 disposed on the outer skin layer 300 to reinforce and protect the outer skin layer and having an anti-fingerprint (AF) function;

An anti-curl layer 400 disposed under the outer skin layer 300, increasing hardness of the outer layer and preventing reverse curl;

a stress relief layer 500 disposed under the anti-curl layer 400, having a higher elongation and lower storage elastic modulus (G') than the outer skin layer, and relieving stress of the outer skin layer;

A UV curable deformable adhesive layer 600 disposed under the stress relief layer 500, cured by ultraviolet (UV) light, and acting as an adhesive layer while being molded to match the shape of the display surface, and having properties of a deformable material and an adhesive at the same time; and

Peeling layers 100 and 700 disposed above the anti-fingerprint reinforcement layer 200 and below the UV curable deformable adhesive layer 600 to protect them and remove during use,

A protective film for 3D window glass is provided.

According to one embodiment of the present invention, the outer skin layer 300

It may include at least one synthetic resin film selected from the group consisting of polyethylene terephthalate (PET), polypropylene (PP), non-stretched polypropylene (CPP), polyurethane (PU), and polyolefin (PO).

According to one embodiment of the present invention, the thickness of the skin layer 300 may be 15 ㎛ to 100 ㎛.

According to one embodiment of the present invention, the anti-fingerprint reinforcement layer 200

It may include at least one anti-fingerprint and surface-reinforcing resin composition selected from the group consisting of an acrylic resin composition, a urethane-based resin composition, and a silicone-based resin composition.

According to one embodiment of the present invention, the anti-fingerprint reinforcement layer 200 may have a thickness of 1 μm to 20 μm.

According to one embodiment of the present invention, the anti-curl layer 400

An acrylic copolymer resin having a glass transition temperature of 0 °C or less; photoreactive bifunctional oligomers having a glass transition temperature of 0 °C or less; And it may be made of an anti-curl composition containing a photoinitiator.

According to one embodiment of the present invention, the thickness of the anti-curl layer 400 may be 10 μm to 40 μm.

According to one embodiment of the present invention, the stress relieving layer 500

It may be made of a stress relief composition including thermosetting acrylic or thermoplastic polyurethane (TPU).

According to one embodiment of the present invention, the thickness of the stress relief layer 500 may be 20 ㎛ to 60 ㎛.

According to one embodiment of the present invention, the UV curable deformable adhesive layer 600

having deformable material and adhesive properties at the same time

It may be made of a photocurable adhesive composition for 3D window glass.

According to one embodiment of the present invention, the thickness of the UV curable deformable adhesive layer 600 may be 20 μm to 60 μm.

According to one embodiment of the present invention, the photocurable adhesive composition for 3D window glass

An acrylic copolymer resin having a glass transition temperature of 0 °C or less; photoreactive bifunctional oligomers having a glass transition temperature of 0 °C or less; And a photoinitiator; may include.

According to one embodiment of the present invention, the photocurable adhesive composition for 3D window glass

Regarding 100 parts by weight of an acrylic copolymer resin having a glass transition temperature of 0 ° C or less

2.8 parts by weight to 8.3 parts by weight of a photoreactive multifunctional oligomer having a glass transition temperature of 0 °C or less; and

0.1 part by weight to 7 parts by weight of a photoinitiator; may include.

According to one embodiment of the present invention, the acrylic copolymer resin having a glass transition temperature of 0 ° C or less is

It may be a copolymer resin composed of one or more acrylic compounds selected from the group consisting of 2-Ethylhexylacrylate, n-Butylacrylate, 2-hydroxymethacrylate, and n-Dimethylacrylamide.

According to one embodiment of the present invention, the photoreactive bifunctional oligomer having a glass transition temperature of 0 ° C or less is

It may be a polyoxyalkylene block-containing photoreactive bifunctional oligomer.

According to one embodiment of the present invention, the polyoxyalkylene block-containing photoreactive bifunctional oligomer

It may be polyethylene glycol (PEG)-modified acrylate of Formula 1 or polypropylene glycol (PPG)-modified acrylate of Formula 2.

[Formula 1]

[Formula 2]

In Formula 1 and Formula 2,

X is hydrogen, halogen, C1-C16 alkyl or C1-C20 aryl, and n is a number from 200 to 1000.

According to one embodiment of the present invention, the release layer 100 or 700 may be a silicone release film.

In addition, the present invention

(1) preparing a corona-treated outer skin layer 300 made of a heat-deformable synthetic resin film, which serves as a support film;

(2) An anti-fingerprint reinforcement layer 200 having an anti-fingerprint (AF) function is disposed on the corona-treated outer layer 300 to reinforce and protect the outer skin layer 200 with a micro gravure coater. Preparing a coating with a resin composition for strengthening;

(3) preparing an anti-curl layer 400 disposed under the outer skin layer 300, increasing hardness of the outer layer and preventing reverse curl by coating an anti-curl composition with a slot die coater;

(4) a stress relief layer 500 disposed under the anti-curl layer 400, having a higher elongation and a lower storage elastic modulus (G′) than the outer skin layer, and relieving the stress of the outer skin layer 500 with a slot die coater Preparing a stress relief composition by coating;

(5) preparing a UV curable deformable adhesive layer 600 disposed under the stress relief layer 500, cured by ultraviolet (UV) light and molded to match the shape of the display surface, acting as an adhesive layer, and having properties of a deformable material and an adhesive at the same time by coating a photocurable adhesive composition for 3D window glass with the slow die coater; and

(6) laminating release layers (100, 700), which are respectively disposed above the anti-fingerprint reinforcement layer 200 and below the UV curable deformable adhesive layer 600 and are removed during use while protecting them, during the manufacturing process of the anti-fingerprint reinforcement layer 200 and the UV curable deformable adhesive layer 600, respectively, above the anti-fingerprint reinforcement layer 200 and below the UV curable deformable adhesive layer 600;

A method for manufacturing a protective film for 3D window glass is provided.

According to one embodiment of the present invention, the step of preparing the anti-fingerprint reinforcement layer 200 in step (2) by coating an anti-fingerprint and surface-reinforcing resin composition with a micro gravure coater

After coating the corona layer of the outer skin layer 300 with a micro gravure coater that coats the corona layer with a micro-layer thickness of a resin composition for anti-fingerprint and surface reinforcement,

The anti-fingerprint and surface-reinforcing resin composition is photocured or thermally cured to form an anti-fingerprint reinforcement layer 200,

A process of laminating the anti-fingerprint reinforcement layer 200 and the release layer 100 may be included.

According to one embodiment of the present invention, the process of forming the anti-fingerprint reinforcement layer 200 by photocuring or thermally curing the anti-fingerprint and surface-reinforcing resin composition

photocuring the anti-fingerprint and surface-reinforcing resin composition at a temperature of 30 ° C to 100 ° C with a UV lamp intensity of 200 mJ to 3000 mJ;

or a step of thermally curing the anti-fingerprint and surface-reinforcing resin composition at a temperature of 60 °C to 170 °C.

According to one embodiment of the present invention, the step of (3) coating the anti-curl layer 400 to increase the hardness of the outer skin layer and prevent reverse curl by coating the anti-curl composition with a slot die coater

After coating the opposite surface of the outer skin layer 300 on which the anti-fingerprint reinforcement layer 200 is formed, the anti-curl composition is supplied through a nozzle-shaped fine metal plate and coated with a slot die coater,

A process of forming the anti-curl layer 400 by thermally curing the anti-curl composition may be included.

According to one embodiment of the present invention, the process of forming the anti-curl layer 400 by thermally curing the anti-curl composition

It may include; a step of thermally curing the anti-curl composition at a temperature of 60 ° C to 170 ° C.

According to one embodiment of the present invention, the step of preparing the stress relief layer 500 for relieving the stress of the outer skin layer in step (4) by coating the stress relief composition with a slot die coater

The anti-fingerprint reinforcement layer 200 is formed on the opposite surface of the outer layer 300, the anti-curl layer 400, and coated with a slot die coater for coating by supplying the stress relieving composition between nozzle-shaped fine metal plates,

A process of photocuring or thermally curing the stress relieving composition to form the stress relieving layer 500 may be included.

According to one embodiment of the present invention, the process of forming the stress relief layer 500 by photocuring or thermally curing the stress relief composition

photocuring the stress-relieving composition at a temperature of 30 °C to 100 °C with a UV lamp intensity of 200 mJ to 3000 mJ;

or a step of thermally curing the stress relief composition at a temperature of 60 °C to 170 °C.

According to one embodiment of the present invention, the step of preparing the UV curable deformable adhesive layer 600 in step (5) by coating the photocurable adhesive composition for 3D window glass with the slot die coater

After coating the top of the stress relief layer 500 with a slot die coater that supplies and coats the photocurable adhesive composition for 3D window glass between nozzle-shaped fine metal plates,

After photocuring or thermally curing the photocurable adhesive composition for 3D window glass to form a UV curable deformable adhesive layer 600,

A process of laminating the UV curable deformable adhesive layer 600 and the release layer 700 may be included.

According to an embodiment of the present invention, the process of forming the UV curable deformable adhesive layer 600 by photocuring or thermally curing the photocurable adhesive composition for 3D window glass includes:

photocuring the photocurable adhesive composition for 3D window glass at a temperature of 30 ° C to 100 ° C and a UV lamp intensity of 200 mJ to 3000 mJ;

or a step of thermally curing the photocurable adhesive composition for 3D window glass at a temperature of 60 °C to 170 °C.

In addition, the present invention, a glass transition temperature of 0 ℃ or less acrylic copolymer resin; A photoreactive multifunctional oligomer having a glass transition temperature of 0 °C or less; and photoinitiators; Including, having deformable material and adhesive properties at the same time

A photocurable adhesive composition for 3D window glass is provided.

According to the present invention, since a protective film for 3D window glass is provided, which has excellent heat resistance and adhesive strength, and prevents or reduces strain, reverse curl, and surface lifting, the quality is superior.

In addition, since the present invention provides a protective film for 3D window glass having properties of a deformable material and an adhesive at the same time and a photocurable adhesive composition therefor, the process is simple and the physical properties of the protective film are excellent.

In addition, the present invention provides a method for manufacturing a protective film for 3D window glass in which a micro-thick protective film for 3D window glass, which has a 3D shape and is attached for a long period of time, is uniformly coated over a large area using a micro gravure coater or a slot die coater, and then photocured or thermally cured. Thus, process efficiency and economy are high.

The effects of the present invention are not limited to the above effects, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the configuration of the invention described in the claims.

1 is a conceptual diagram showing cross-sectional shapes of 2D, 2.5D and 3D window glasses.
2 is a conceptual diagram showing a case in which a lifting phenomenon occurs at the curved edge portion due to restoration by elasticity because no deformable material is used on a curved window glass, and a case in which the lifting phenomenon does not occur because the deformed shape is maintained at the curved edge portion using a deformable material.
3 is a view showing a layer configuration of a protective film for 3D window glass according to an embodiment of the present invention.
4 is a schematic view of a process for manufacturing an anti-fingerprint reinforcement layer according to an embodiment of the present invention by coating an anti-fingerprint and surface-reinforcing resin composition with a micro gravure coater.
5 is a schematic view of a process for manufacturing an anti-curl layer or a stress relieving layer according to an embodiment of the present invention by coating an anti-curl composition or a stress relieving composition with a slot die coater, respectively.
6 is a schematic view of a process for preparing a UV curable deformable adhesive layer according to an embodiment of the present invention by coating a photocurable adhesive composition for 3D window glass using a slow die coater.

Before describing the present invention in detail, the terms or words used in this specification should not be construed as unconditionally limited to conventional or dictionary meanings, and the inventors of the present invention may appropriately define and use the concept of various terms in order to explain their invention in the best way, and furthermore, it should be understood that these terms or words should be interpreted as meanings and concepts consistent with the technical spirit of the present invention.

That is, the terms used in this specification are only used to describe preferred embodiments of the present invention, and are not intended to specifically limit the contents of the present invention, and these terms are various possibilities of the present invention. It should be noted that these are terms defined in consideration.

In addition, in this specification, it should be understood that singular expressions may include plural expressions unless the context clearly indicates otherwise, and similarly, even if they are expressed in plural numbers, they may include singular meanings.

Throughout the present specification, when a component is described as "including" another component, it may mean that it may further include any other component rather than excluding any other component unless otherwise stated.

In addition, in the following description of the present invention, a detailed description of a configuration that is determined to unnecessarily obscure the subject matter of the present invention, for example, the known technology including the prior art, may be omitted.

Protective film for 3D window glass

The present invention can be explained in more detail with reference to the drawings.

1 is a view showing cross-sectional shapes of 2D, 2.5D and 3D window glasses.

As can be seen in FIG. 1, in the 2D window, both the glass and the display are flat, in the 2.5D window, the display is flat but the edges of the glass are curved, and in the 3D window, the glass and the display are both curved.

Recently, as foldable or bendable displays have been developed, a 3D window may be used as a meaning including all curved or 3D shapes (curved, bent, foldable, rollable).

In addition, FIG. 2 is a conceptual diagram showing a case in which the lifting phenomenon occurs at the curved edge portion due to restoration by elasticity because no deformable material is used on the curved window glass, and a case in which the lifting phenomenon does not occur because the deformed shape is maintained at the curved edge portion using the deformable material.

Referring to FIG. 2 , when a deformable material is used, the deformed shape is maintained at the curved edge portion, so that lifting may not occur.

Therefore, the present invention provides a protective film for 3D window glass using a deformable material and having adhesive properties at the same time,

The protective film for the 3D window glass,

an outer skin layer 300 acting as a support film and made of a heat-deformable synthetic resin film;

An anti-fingerprint reinforcement layer 200 disposed on the outer skin layer 300 to reinforce and protect the outer skin layer and having an anti-fingerprint (AF) function;

An anti-curl layer 400 disposed under the outer skin layer 300, increasing hardness of the outer layer and preventing reverse curl;

a stress relief layer 500 disposed under the anti-curl layer 400, having a higher elongation and lower storage elastic modulus (G') than the outer skin layer, and relieving stress of the outer skin layer;

A UV curable deformable adhesive layer 600 disposed under the stress relief layer 500, cured by ultraviolet (UV) light, and acting as an adhesive layer while being molded to match the shape of the display surface, and having properties of a deformable material and an adhesive at the same time; and

Exfoliation layers 100 and 700 disposed above the anti-fingerprint reinforcement layer 200 and below the UV curable deformable adhesive layer 600 to protect them and remove during use.

Here, the protective film for 3D window glass is a protective film for 3D window glass that realizes a 3D shape well, has excellent heat resistance and adhesion, and prevents or reduces stress deformation, reverse curling, and surface lifting, and has properties of a deformable material and an adhesive at the same time.

At this time, the reverse curl refers to a phenomenon in which the film is rolled up.

3 is a view showing the layer configuration of a protective film for 3D window glass according to an embodiment of the present invention. The protective film includes a release layer 100, an anti-fingerprint reinforcement layer 200, an outer skin layer 300, a curl prevention layer 400, a stress relief layer 500, a UV curable deformable adhesive layer 600, and a release layer 700 in sequence.

Here, the outer skin layer 300 is

It may include at least one synthetic resin film selected from the group consisting of polyethylene terephthalate (PET), polypropylene (PP), non-stretched polypropylene (CPP), polyurethane (PU), and polyolefin (PO).

In addition, the outer skin layer 300 may have a thickness of 15 μm to 100 μm. Preferably, the thickness of the outer layer 300 may be 20 μm to 60 μm, more preferably, the thickness of the outer layer 300 may be 20 μm to 50 μm.

In the present invention, the outer skin layer 300 is a synthetic resin film having fluidity, preferably a hard synthetic resin film, and serves to protect the deformable material layer while supporting the protective film. The synthetic resin constituting the skin layer is not particularly limited, but polyethylene terephthalate (PET), polypropylene (PP), non-stretched polypropylene (CPP), polyurethane (PU), polyolefin (PO), and the like may be used. Considering the role of the support layer and/or the protective layer, the thickness of the skin layer may be adjusted to a range of 15 μm to 100 μm, preferably 20 μm to 60 μm, and more preferably 20 μm to 50 μm.

In the present invention, the anti-fingerprint reinforcement layer 200

It may include at least one anti-fingerprint and surface-reinforcing resin composition selected from the group consisting of an acrylic resin composition, a urethane-based resin composition, and a silicone-based resin composition.

In addition, the anti-fingerprint reinforcement layer 200 may have a thickness of 1 μm to 20 μm. Preferably, the thickness of the anti-fingerprint reinforcement layer 200 may be 2 μm to 10 μm, and more preferably, the thickness of the anti-fingerprint reinforcement layer 200 may be 2.5 μm to 5 μm.

In the present invention, the anti-curl layer 400

An acrylic copolymer resin having a glass transition temperature of 0 °C or less; photoreactive bifunctional oligomers having a glass transition temperature of 0 °C or less; And it may be made of an anti-curl composition containing a photoinitiator.

In addition, the thickness of the anti-curl layer 400 may be 10 μm to 40 μm. Preferably, the thickness of the anti-curl layer 400 may be 15 μm to 35 μm, and more preferably, the thickness of the anti-curl layer 400 may be 10 μm to 30 μm.

In addition, the anti-curl composition

Regarding 100 parts by weight of an acrylic copolymer resin having a glass transition temperature of 0 ° C or less

2.8 parts by weight to 8.3 parts by weight of a photoreactive multifunctional oligomer having a glass transition temperature of 0 °C or less; and

0.1 part by weight to 7 parts by weight of a photoinitiator; may include.

Here, the acrylic copolymer resin having a glass transition temperature of 0 ° C or less is

It may be a copolymer resin composed of one or more acrylic compounds selected from the group consisting of 2-Ethylhexylacrylate, n-Butylacrylate, 2-hydroxymethacrylate, and n-Dimethylacrylamide.

In addition, the photoreactive bifunctional oligomer having a glass transition temperature of 0 °C or less may be a polyoxyalkylene block-containing photoreactive bifunctional oligomer.

And, the polyoxyalkylene block-containing photoreactive bifunctional oligomer

It may be polyethylene glycol (PEG)-modified acrylate of Formula 1 or polypropylene glycol (PPG)-modified acrylate of Formula 2 below.

[Formula 1]

[Formula 2]

In Formula 1 and Formula 2,

X is hydrogen, halogen, C1-C16 alkyl or C1-C20 aryl, and n is a number from 200 to 1000.

At this time, in Formula 1 and Formula 2,

X represents hydrogen, halogen, C1-C16 alkyl or C1-C20 aryl, preferably CH ₃ , n is a number from 200 to 1000, preferably from 300 to 900, more preferably from 400 to 800.

Here, the anti-curl layer 400 is made of a polymer that increases the hardness of the outer layer and prevents reverse curl, thereby increasing resistance to external impact and relieving reverse curl of the outer layer, so that the adhesive strength of the protective film can be improved. The anti-curl composition may include an acrylic copolymer resin having a glass transition temperature of 0 °C or less; photoreactive bifunctional oligomers having a glass transition temperature of 0 °C or less; And a photoinitiator; may include.

The thickness of the anti-curl layer may be selected in the range of 10 μm to 40 μm, preferably in the range of 15 μm to 35 μm, and more preferably in the range of 10 μm to 30 μm, in consideration of the material and thickness of the outer skin layer.

In addition, the stress relieving layer 500

It may be made of a stress relief composition including thermosetting acrylic or thermoplastic polyurethane (TPU).

Also, the thickness of the stress relieving layer 500 may be 20 μm to 60 μm. Preferably, the thickness of the stress relieving layer 500 may be 25 μm to 50 μm, and more preferably, the thickness of the stress relieving layer 500 may be 28 μm to 45 μm.

In the present invention, the stress relieving layer 500 is made of a polymer having a higher elongation than the outer skin layer and a lower storage elastic modulus (G '), so that the outer layer made of synthetic resin can play a role in relieving stress or shear force caused by heat or shrinkage or deformation in a high temperature and high humidity environment during use, and as a result, the adhesive strength of the protective film can be improved. Polymers usable in the stress relieving layer may include thermosetting acrylic or thermoplastic polyurethane. The thickness of the stress relief layer may be selected from the range of 20 μm to 60 μm, preferably from 25 μm to 50 μm, and more preferably from 28 μm to 45 μm in consideration of the material and thickness of the outer skin layer.

In the present invention, the UV curable deformable adhesive layer 600 has properties of a deformable material and an adhesive at the same time.

It may be made of a photocurable adhesive composition for 3D window glass.

Here, the photocurable adhesive composition for 3D window glass is

An acrylic copolymer resin having a glass transition temperature of 0 °C or less; photoreactive bifunctional oligomers having a glass transition temperature of 0 °C or less; And a photoinitiator; may include.

In addition, the photocurable adhesive composition for 3D window glass

Regarding 100 parts by weight of an acrylic copolymer resin having a glass transition temperature of 0 ° C or less

2.8 parts by weight to 8.3 parts by weight of a photoreactive multifunctional oligomer having a glass transition temperature of 0 °C or less; and

0.1 part by weight to 7 parts by weight of a photoinitiator; may include.

Here, the UV curable deformable adhesive layer 600 may have a thickness of 20 μm to 60 μm. Preferably, the thickness of the UV curable deformable adhesive layer 600 may be 25 μm to 50 μm, and more preferably, the thickness of the UV curable deformable adhesive layer 600 may be 28 μm to 45 μm.

According to one embodiment of the present invention, the acrylic copolymer resin having a glass transition temperature of 0 ° C or less is

It may be a copolymer resin composed of one or more acrylic compounds selected from the group consisting of 2-Ethylhexylacrylate, n-Butylacrylate, 2-hydroxymethacrylate, and n-Dimethylacrylamide.

According to one embodiment of the present invention, the photoreactive bifunctional oligomer having a glass transition temperature of 0 °C or less may be a polyoxyalkylene block-containing photoreactive bifunctional oligomer.

Here, the polyoxyalkylene block-containing photoreactive bifunctional oligomer is

It may be polyethylene glycol (PEG)-modified acrylate of Formula 1 or polypropylene glycol (PPG)-modified acrylate of Formula 2.

According to one embodiment of the present invention, the storage elastic modulus (G ') value of the UV curable deformable adhesive layer 600 before UV curing is 1 ~ 3 × 10 ⁴ Pa to the storage elastic modulus (G ') after UV curing. It can be increased to 8 ~ 11 × 10 ⁴ Pa.

According to one embodiment of the present invention, the release layer 100 or 700 may be a silicone release film.

Photocurable adhesive composition for 3D window glass

In addition, the present invention is an acrylic copolymer resin having a glass transition temperature of 0 ° C or less; A photoreactive multifunctional oligomer having a glass transition temperature of 0 °C or less; and photoinitiators; It provides a photocurable adhesive composition for 3D window glass having properties of a deformable material and an adhesive at the same time.

The photocurable adhesive composition for 3D window glass according to an embodiment of the present invention can simultaneously express the properties of a deformable material and an adhesive, and can increase the modulus to an appropriate level after UV curing, so that the initial adhesive strength before UV curing is low, but the adhesive strength after UV curing can be very high, thereby exhibiting excellent properties as a deformable material.

In the photocurable adhesive composition according to an embodiment of the present invention, the photoreactive multifunctional oligomer plays an important role in increasing the modulus, and preferably has a glass transition temperature (Tg) of 0 ° C or less, preferably -10 ° C or less, more preferably -20 ° C or less. Polyoxyalkylene-modified bifunctional oligomers can be used.

Here, the acrylic copolymer resin having a glass transition temperature of 0 ° C or less of the photocurable adhesive composition for 3D window glass is

It may be a copolymer resin composed of one or more acrylic compounds selected from the group consisting of 2-Ethylhexylacrylate, n-Butylacrylate, 2-hydroxymethacrylate, and n-Dimethylacrylamide.

In addition, the photoreactive multifunctional oligomer having a glass transition temperature of 0°C or less in the photocurable adhesive composition for 3D window glass may be a polyoxyalkylene block-containing photoreactive bifunctional oligomer.

In addition, the polyoxyalkylene block-containing photoreactive bifunctional oligomer of the photocurable adhesive composition for 3D window glass may be polyethylene glycol (PEG)-modified acrylate of Formula 1 or polypropelene glycol (PPG) of Formula 2-modified acrylate.

In addition, the photoinitiator of the photocurable adhesive composition for 3D window glass

2,4,6-Trimethyl-benzoyldiphenyldiphenylphosphine oxide (2,4,6-Trimethyl-benzoyl-diphenyl-diphenyl Phosphine oxide, TPO), 4,4'-bisdiethylamino benz

It may be one or more selected from the group consisting of 4,4'-Bis(diethylamino)benzophenone, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

In addition, the photocurable adhesive composition for 3D window glass

Regarding 100 parts by weight of an acrylic copolymer resin having a glass transition temperature of 0 ° C or less

2.8 parts by weight to 8.3 parts by weight of a photoreactive multifunctional oligomer having a glass transition temperature of 0 °C or less; and

0.1 part by weight to 7 parts by weight of a photoinitiator; may include.

Manufacturing method of protective film for 3D window glass

In addition, the method for manufacturing a protective film for 3D window glass of the present invention

(1) preparing a corona-treated outer skin layer 300 made of a heat-deformable synthetic resin film, which serves as a support film;

(2) An anti-fingerprint reinforcement layer 200 having an anti-fingerprint (AF) function is disposed on the corona-treated outer layer 300 to reinforce and protect the outer skin layer 200 with a micro gravure coater. Preparing a coating with a resin composition for strengthening;

(3) preparing an anti-curl layer 400 disposed under the outer skin layer 300, increasing hardness of the outer layer and preventing reverse curl by coating an anti-curl composition with a slot die coater;

(4) a stress relief layer 500 disposed under the anti-curl layer 400, having a higher elongation and a lower storage elastic modulus (G′) than the outer skin layer, and relieving the stress of the outer skin layer 500 with a slot die coater Preparing a stress relief composition by coating;

(5) preparing a UV curable deformable adhesive layer 600 disposed under the stress relief layer 500, cured by ultraviolet (UV) light and molded to match the shape of the display surface, acting as an adhesive layer, and having properties of a deformable material and an adhesive at the same time by coating a photocurable adhesive composition for 3D window glass with the slow die coater; and

(6) Laminating release layers 100 and 700, which are respectively disposed above the anti-fingerprint reinforcement layer 200 and below the UV curable deformable adhesive layer 600 to protect them and to be removed during use, respectively, on the anti-fingerprint reinforcement layer 200 and below the UV curable deformable adhesive layer 600 during the manufacturing process of the anti-fingerprint reinforcement layer 200 and the UV curable deformable adhesive layer 600;

Here, the method for manufacturing a protective film for 3D window glass is a method for manufacturing a protective film for 3D window glass that uniformly manufactures a protective film for 3D window glass having a micro-thickness over a large area that well realizes a 3D shape and is attached for a long period of time.

According to one embodiment of the present invention, the step of preparing the anti-fingerprint reinforcement layer 200 in step (2) by coating an anti-fingerprint and surface-reinforcing resin composition with a micro gravure coater

After coating the corona layer of the outer skin layer 300 with a micro gravure coater that coats the corona layer with a micro-layer thickness of a resin composition for anti-fingerprint and surface reinforcement,

The anti-fingerprint and surface-reinforcing resin composition is photocured or thermally cured to form an anti-fingerprint reinforcement layer 200,

A process of laminating the anti-fingerprint reinforcement layer 200 and the release layer 100 may be included.

Here, the coating method using the micro gravure coater miniaturizes the radius of the coating roll of the micro gravure coater to minimize the range of the roll surface and the anti-fingerprint and surface-strengthening resin composition, thereby minimizing the anti-fingerprint and surface-strengthening resin composition. It is a precision coating method of uniformly applying a micro-thick thin film.

4 is a schematic view of a process for manufacturing an anti-fingerprint reinforcement layer according to an embodiment of the present invention by coating an anti-fingerprint and surface-reinforcing resin composition with a micro gravure coater.

Referring to FIG. 4, while unwinding the corona layer of the outer skin layer 300 upward, an anti-fingerprint and surface-strengthening resin composition is uniformly coated with a micro-thick thin film with a micro gravure coater, and then transferred to a chamber to photocuring or thermally curing to form an anti-fingerprint reinforcement layer 200, and then laminate the anti-fingerprint reinforcement layer 200 and the peeling layer 100, and then rewind and store.

In addition, the process of forming the anti-fingerprint reinforcement layer 200 by photocuring or thermally curing the anti-fingerprint and surface-reinforcing resin composition

photocuring the anti-fingerprint and surface-reinforcing resin composition at a temperature of 30 ° C to 100 ° C with a UV lamp intensity of 200 mJ to 3000 mJ;

or a step of thermally curing the anti-fingerprint and surface-reinforcing resin composition at a temperature of 60 °C to 170 °C.

Here, the temperature of the photocuring process may be preferably 40 °C to 90 °C, more preferably 50 °C to 80 °C.

In addition, the UV lamp intensity of the photocuring process may be preferably 300 mJ to 2000 mJ, more preferably 500 mJ to 1500 mJ.

In addition, the temperature of the thermal curing process may be preferably 70 ° C to 160 ° C, more preferably 80 ° C to 150 ° C, and for example, a stepwise temperature cycle such as 80 ° C - 100 ° C - 130 ° C - 150 ° C - 130 ° C -80 ° C.

According to one embodiment of the present invention, the step of (3) coating the anti-curl layer 400 to increase the hardness of the outer skin layer and prevent reverse curl by coating the anti-curl composition with a slot die coater

After coating the opposite surface of the outer skin layer 300 on which the anti-fingerprint reinforcement layer 200 is formed, the anti-curl composition is supplied through a nozzle-shaped fine metal plate and coated with a slot die coater,

A process of forming the anti-curl layer 400 by thermally curing the anti-curl composition may be included.

Here, the coating method using the slot die coater is a method of coating by supplying the liquid anti-curl composition between nozzle-shaped metal plates using a pump.

In addition, the process of forming the anti-curl layer 400 by thermally curing the anti-curl composition

It may include; a step of thermally curing the anti-curl composition at a temperature of 60 ° C to 170 ° C.

Here, the temperature of the thermal curing process may be preferably 70 ° C to 160 ° C, more preferably 80 ° C to 150 ° C, and for example, a stepwise temperature cycle such as 80 ° C -100 ° C - 130 ° C - 150 ° C - 130 ° C -80 ° C.

5 is a schematic diagram of a process for preparing an anti-curl layer according to an embodiment of the present invention by coating an anti-curl composition with a slot die coater.

Referring to FIG. 5, the opposite surface of the outer layer 300 on which the anti-fingerprint reinforcement layer 200 is exposed by unwinding the backup roll is coated with a slot die coater for coating by supplying the anti-curl composition through a nozzle-shaped fine metal plate, and then transporting the coated anti-curl composition to a dry chamber, heat-curing it in the dry chamber, forming the anti-curl layer 400, which is a product, and then rewinding and storing.

In addition, the process of forming the anti-curl layer 400 by thermally curing the anti-curl composition

It may include; a step of thermally curing the anti-curl composition at a temperature of 60 ° C to 170 ° C.

In addition, the temperature of the thermal curing process may be preferably 70 ° C to 160 ° C, more preferably 80 ° C to 150 ° C, and for example, a stepwise temperature cycle such as 80 ° C - 100 ° C - 130 ° C - 150 ° C - 130 ° C -80 ° C.

According to one embodiment of the present invention, the step of preparing the stress relief layer 500 for relieving the stress of the outer skin layer in step (4) by coating the stress relief composition with a slot die coater

The anti-fingerprint reinforcement layer 200 is formed on the opposite surface of the outer layer 300, the anti-curl layer 400, and coated with a slot die coater for coating by supplying the stress relieving composition between nozzle-shaped fine metal plates,

A process of photocuring or thermally curing the stress relieving composition to form the stress relieving layer 500 may be included.

Here, the coating method using the slot die coater is a method of supplying the liquid stress relief composition between nozzle-shaped metal plates using a pump and coating the composition.

5 is a schematic view of a process for manufacturing a stress relief layer according to an embodiment of the present invention by coating a stress relief composition with a slot die coater.

Referring to FIG. 5, the anti-fingerprint layer 200 exposed by unwinding the back-up roll is coated on the anti-curl layer 400, which is the opposite side of the outer layer 300 on which the anti-fingerprint reinforcing layer 200 is formed, by using a pump to supply the stress-relieving composition between the nozzle-shaped fine metal plates to coat the top, and then transferring the coated stress-relieving composition to a dry chamber to photocuring or thermally curing in the dry chamber to form a product, the stress-relieving layer 500. After that, rewind and store.

In addition, the process of forming the stress relief layer 500 by photocuring or thermally curing the stress relief composition

photocuring the stress-relieving composition at a temperature of 30 °C to 100 °C with a UV lamp intensity of 200 mJ to 3000 mJ;

or a step of thermally curing the stress relief composition at a temperature of 60 °C to 170 °C.

Here, the temperature of the photocuring process may be preferably 40 °C to 90 °C, more preferably 50 °C to 80 °C.

In addition, the UV lamp intensity of the photocuring process may be preferably 300 mJ to 2000 mJ, more preferably 500 mJ to 1500 mJ.

In addition, the temperature of the thermal curing process may be preferably 70 ° C to 160 ° C, more preferably 80 ° C to 150 ° C, and for example, a stepwise temperature cycle such as 80 ° C - 100 ° C - 130 ° C - 150 ° C - 130 ° C -80 ° C.

In addition, according to an embodiment of the present invention, the step of preparing the UV curable deformable adhesive layer 600 in step (5) by coating the photocurable adhesive composition for 3D window glass with the slot die coater

After coating the top of the stress relief layer 500 with a slot die coater that supplies and coats the photocurable adhesive composition for 3D window glass between nozzle-shaped fine metal plates,

After photocuring or thermally curing the photocurable adhesive composition for 3D window glass to form a UV curable deformable adhesive layer 600,

A process of laminating the UV curable deformable adhesive layer 600 and the release layer 700 may be included.

Here, the coating method using the slot die coater is a method of coating by supplying a liquid photocurable adhesive composition for 3D window glass between nozzle-shaped metal plates using a pump.

6 is a schematic view of a process for preparing a UV curable deformable adhesive layer according to an embodiment of the present invention by coating a photocurable adhesive composition for 3D window glass using a slow die coater.

Referring to FIG. 6, the top of the stress relieving layer 500 exposed by unwinding the back-up roll is coated with a slot die coater that supplies the photocurable adhesive composition for 3D window glass through a nozzle-shaped metal plate using a pump and then coats the coated photocurable adhesive composition for 3D window glass. After laminating the curable deformable adhesive layer 600 and the release layer 600, it is rewinded and stored as a product.

In addition, the process of forming the UV curable deformable adhesive layer 600 by photocuring or thermally curing the photocurable adhesive composition for 3D window glass is

photocuring the photocurable adhesive composition for 3D window glass at a temperature of 30 ° C to 100 ° C and a UV lamp intensity of 200 mJ to 3000 mJ;

or a step of thermally curing the photocurable adhesive composition for 3D window glass at a temperature of 60 °C to 170 °C.

Here, the temperature of the photocuring process may be preferably 40 °C to 90 °C, more preferably 50 °C to 80 °C.

In addition, the UV lamp intensity of the photocuring process may be preferably 300 mJ to 2000 mJ, more preferably 500 mJ to 1500 mJ.

In addition, the temperature of the thermal curing process may be preferably 70 ° C to 160 ° C, more preferably 80 ° C to 150 ° C, and for example, a stepwise temperature cycle such as 80 ° C - 100 ° C - 130 ° C - 150 ° C - 130 ° C -80 ° C.

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are intended to explain the present invention in more detail, and the scope of the present invention is not limited by the following examples. The following examples may be appropriately modified or changed by those skilled in the art within the scope of the present invention.

<Example>

<Examples 1 to 7> Protective film using diacrylate having a Tg of 0 ° C or less

An acrylic resin was synthesized by solution polymerization of 2-Ethylhexylacrylate, n-Butylacrylate, 2-hydroxymethacrylate, and n-Dimethylacrylamide at a ratio of 15/72/3/10.

The obtained acrylic resin exhibited a glass transition temperature (Tg) of -43 °C, a solid content of 39 to 41 wt%, and a viscosity of 3000 to 5000 cps.

A photocurable adhesive coating composition for 3D window glass was prepared by mixing 4.5 parts by weight of a bifunctional diacrylate having a glass transition temperature (Tg) of 0 ° C or lower as a photocurable bifunctional oligomer with 100 parts by weight of the acrylic resin prepared above, and adding 0.83 parts by weight of KONNATE L75 (45%) and 0.3 parts by weight of a photoinitiator TPO as a curing agent.

The photocurable adhesive coating composition for 3D window glass was slot die coated on a PET film (thickness: 25 μm) as an outer layer and dried to prepare a UV curable deformable adhesive layer having a thickness of 40 μm, aged at 60 ° C. for 3 days, and then photocured to prepare a protective film composed of an outer skin layer (PET, 25 μm) and a UV curable deformable adhesive layer. The measured physical properties are shown in Table 1.

<Comparative Examples A-1 to A-6> Protective film using a photocurable bifunctional oligomer for each type having a Tg of 0 ° C or higher

In the same manner as in Example 1, an acrylic resin was prepared while changing the Tg of the photocurable bifunctional oligomer to 0 °C or higher.

A protective film composed of an outer skin layer (PET, 25 μm) and a UV curable deformable adhesive layer was prepared using the acrylic resin, and physical properties were measured. The measured physical properties are shown in Table 2.

<Test Example 1> Initial adhesive strength before UV curing, adhesive strength after UV curing, deformability and appearance

Using the protective films made of the PET skin layer and the deformable adhesive layer prepared in Examples 1 to 7 and Comparative Examples A1 to A6, initial adhesion before UV curing, adhesion after UV curing, deformability and appearance were tested, and the results are shown in Tables 1 and 2 below.

The test method is as follows.

Initial adhesion: After cutting the protective film into a size of 25 cm in length and 1 inch in width, it was laminated to SUS 303 by reciprocating once with a 2 kg laminating roll at a speed of 300 mm per minute, and then left at room temperature for 30 minutes. The specimen attached to SUS 304 was peeled off at a speed of 300 mm per minute using the same Shimadzu EZ-SX UTM to measure the adhesive strength.

Adhesion after UV curing: A protective film was attached to a SUS 303 substrate, and UV 1000 mJ was irradiated, and then the adhesion was measured by the same test method as the initial adhesion.

Deformability: A protective film was attached to a 3D cover glass having a curved surface (R value of curvature: 3.3 mm), and the degree of deformation was visually evaluated. If there is no lifting phenomenon in the bent part, it was evaluated as good.

Appearance: The protective film was attached to the substrate, and after UV curing, transparency and traces after removing the protective film were visually evaluated.

As can be seen in Table 1, when the amount of diacrylate having a Tg of 0 ° C. or less was fixed at 4.5 parts by weight and the type of diacrylate having a Tg of 0 ° C. or less was changed, a haze problem occurred when the Tg was -37 ° C. or less.

As can be seen in Table 2, when the amount of diacrylate having a Tg of 0 ° C. or higher was fixed at 4.5 parts by weight and the type of diacrylate having a Tg of 0 ° C. or higher was changed, a haze problem occurred when the Tg was 111 ° C. or higher, and a deformation problem occurred due to a decrease in adhesion when the Tg was 0 ° C. or higher.

<Example 8> Protective film using polypropylene diacrylate

A coating composition was prepared in the same manner as in Example 1, except that 6.5 parts by weight of polypropylene glycol 400 diacrylate (trade name: Miramer 2040) having a glass transition temperature (Tg) of 0 ° C or less as a photocurable bifunctional oligomer was mixed with 100 parts by weight of the acrylic resin of Example 1.

The coating composition was slot die coated on a PET film (thickness: 25 μm) and dried to prepare a UV curable deformable adhesive layer having a thickness of 40 μm, aged at 60° C. for 3 days, and then photocured to prepare a protective film composed of the outer skin layer (PET, 25 μm) and the UV curable deformable adhesive layer. The measured physical properties are shown in Table 3.

<Comparative Examples B-1 to B-3> Protective films using different photocurable bifunctional oligomer contents

Acrylic resins were prepared in the same manner as in Example 1, but by changing the type of photocurable bifunctional oligomer.

Using the acrylic resin, a protective film composed of an outer skin layer (PET, 25 μm) and a UV curable deformable adhesive layer was prepared, and physical properties were measured. The results are shown in Table 3 below.

<Test Example 2> Initial adhesive strength before UV curing, adhesive strength after UV curing, deformability and appearance

Using the protective films made of the PET skin layer and the deformable adhesive layer prepared in Example 1, Example 8 and Comparative Examples B1 to B3, the initial adhesive force before UV curing, the adhesive force after UV curing, deformability and appearance were tested, and the results are shown in Table 3 below.

Each test method is the same as the method described in Test Example 1 above.

As can be seen in Table 3, when the amount of polypropylene glycol 400 diacrylate (trade name Miramer 2040) is very small, 2.5 parts by weight, deformation defects were exhibited, and as the amount of polypropylene glycol diacrylate (trade name Miramer 2040) increased to 8.5 or more, the initial adhesive strength decreased and haze problems occurred.

<Example 9> Protective film using polyethylene diacrylate

A coating composition was prepared in the same manner as in Example 2, except that 6.5 parts by weight of polyethylene glycol diacrylate (trade name: Miramer M280) having a glass transition temperature (Tg) of 0 ° C or less as a photocurable bifunctional oligomer was mixed with 100 parts by weight of the acrylic resin of Example 2.

The coating composition was slot die coated on a PET film (thickness: 25 μm) and dried to prepare a UV curable deformable adhesive layer having a thickness of 40 μm, aged at 60° C. for 3 days, and then photocured to prepare a protective film composed of the outer skin layer (PET, 25 μm) and the UV curable deformable adhesive layer. The measured physical properties are shown in Table 4.

<Comparative Examples C-1 to C-3> Protective films using different photocurable bifunctional oligomer contents

In the same manner as in Example 2, acrylic resins were prepared while changing the content of the photocurable bifunctional oligomer.

Using the acrylic resin, a protective film composed of an outer skin layer (PET, 25 μm) and a UV curable deformable adhesive layer was prepared, and physical properties were measured. The results are shown in Table 4 below.

<Test Example 3> Initial adhesive strength before UV curing, adhesive strength after UV curing, deformability and appearance

Using the protective films made of the PET skin layer and the deformable adhesive layer prepared in Examples 2, 9 and Comparative Examples C1 to C3, initial adhesion before UV curing, adhesion after UV curing, deformability and appearance were tested. The results are shown in Table 4 below.

Each test method is the same as the method described in Test Example 1 above.

As can be seen in Table 4, when the amount of polyethylene glycol diacrylate (trade name Miramer M280) was very small, 2.5 parts by weight, deformation was defective, and as the amount of polyethylene glycol diacrylate (trade name Miramer M280) increased, the initial adhesive strength was increased, but a haze problem occurred when 8.5 or more was used.

<Test Example 4> Protective film transmittance, haze, abrasion resistance, pencil hardness and constant temperature and humidity reliability using polypropylene diacrylate

Transmittance, haze, abrasion resistance, pencil hardness and constant temperature and humidity reliability were measured using the protective films made of the PET outer skin layer and the UV curable deformable adhesive layer prepared in Examples 1 and 2 and Comparative Examples B1 to B3, and the results are shown in Table 5 below.

Example 1 Example 8 Comparative Example B-1 Comparative Example B-2 Comparative Example B-3 Acrylic resin (parts by weight) 100 100 100 100 100 L75 (45%) (parts by weight) 0.5 0.5 0.5 0.5 0.5 TPO (parts by weight) 0.3 0.3 0.3 0.3 0.3 MIRIAMER M2040
(Tg: -25℃)
PPG Diacrylate
(parts by weight) 4.5 6.5 2.5 8.5 10.5 Transmittance (%) 91.4 91.6 91.5 89.4 90.1 Haze (%) 0.6 0.6 0.7 2.5 1.9 pencil hardness 2H 2H 2H 1H 2H Wear resistance (times) 30 25 25 30 25 Reliability (constant temperature and humidity) Good Good NG Good N.G Reliability (thermal shock) Good Good NG Good N.G

As can be seen in Table 5, when the amount of polypropylene glycol 400 diacrylate (trade name Miramer 2040) is very low at 2.5 parts by weight and very large at 10.5 parts by weight, the constant temperature and humidity reliability and thermal shock reliability are poor. As the amount of polypropylene glycol 400 diacrylate (trade name Miramer 2040) increases to 8.5 or more, a haze problem occurs.

Therefore, it was confirmed that Example 1 and Example 8 were protective films having higher optical properties and reliability than Comparative Examples B1 to B3.

Here, transmittance and haze were measured with a haze meter.

In addition, abrasion resistance was measured by rubbing the surface of the protective film using 20 mm X 20 mm steel wool with a length of 30 to 40 mm at a pressure of 1000 g and a rotation frequency of 40 rpm with an abrasion resistance meter.

In addition, the pencil hardness was measured by using a Mitsubishi 2H pencil to draw 5 lines, 3 to 5 cm in length, linearly on the surface of the protective film in different directions with a load of 500 g at an angle of 45 °.

The constant temperature and humidity reliability was tested after attaching the protective film to the glass, leaving it in a constant temperature and humidity chamber at 50 ± 2 ° C and 95 ± 2% relative humidity for 72 hours, then taking it out and leaving it at room temperature for 1 hour.

Thermal shock reliability was tested after 72 cycles (1 cycle high/low temperature, 30 minutes each) using a thermal shock tester at -40 ± 2 ° C and +80 ± 2 ° C after attaching the protective film to the glass, then taken out and left at room temperature for 1 hour.

<Test Example 5> Protective film transmittance, haze, abrasion resistance, pencil hardness and constant temperature and humidity reliability using polyethylene diacrylate

Transmittance, haze, abrasion resistance, pencil hardness and constant temperature and humidity reliability were measured using the protective films made of the PET outer skin layer and the UV curable deformable adhesive layer prepared in Examples 2 and 9 and Comparative Examples C1 to C3, and the results are shown in Table 6 below.

Example 2 Example 9 Comparative Example C-1 Comparative Example C-2 Comparative Example C-3 Acrylic resin (parts by weight) 100 100 100 100 100 L75 (45%) (parts by weight) 0.5 0.5 0.5 0.5 0.5 TPO (parts by weight) 0.3 0.3 0.3 0.3 0.3 MIRIAMER M280
(Tg: -25℃)
PEG diacrylate
(parts by weight) 4.5 6.5 2.5 8.5 10.5 Transmittance (%) 91.2 91.1 91.1 89.4 88.5 Haze (%) 0.6 0.5 0.7 2.9 3.0 pencil hardness 2H 2H 1H 2H 2H Wear resistance (times) 30 30 28 31 30 Reliability (constant temperature and humidity) Good Good NG Good Good Reliability (thermal shock) Good Good NG Good Good

As can be seen in Table 6, when the amount of polyethylene glycol diacrylate (trade name Miramer M280) was very small at 2.5 parts by weight, the constant temperature and humidity reliability and thermal shock reliability were poor and pencil hardness was weak. As the amount of polyethylene glycol diacrylate (trade name Miramer M280) increased to 8.5 or more, a haze problem occurred.

Therefore, it was confirmed that Example 2 and Example 9 were protective films having higher optical characteristics and reliability than Comparative Examples C1 to C3.

So far, specific examples of the protective film for 3D window glass according to the present invention, its manufacturing method, and the photocurable adhesive composition for the same have been described, but various modifications are possible within the limits that do not depart from the scope of the present invention. It is obvious.

Therefore, the scope of the present invention should not be limited to the described embodiments and should not be defined, and should be defined by not only the claims to be described later, but also those equivalent to these claims.

That is, the above-described embodiments should be understood as illustrative in all respects and not limiting, and the scope of the present invention is indicated by the claims to be described later rather than the detailed description, and the meaning and scope of the claims and all changes or modifications derived from equivalent concepts should be construed as being included in the scope of the present invention.

Claims (32)

an outer skin layer 300 acting as a support film and made of a heat-deformable synthetic resin film;
An anti-fingerprint reinforcement layer 200 disposed on the outer skin layer 300 to reinforce and protect the outer skin layer and having an anti-fingerprint (AF) function; An anti-curl layer 400 disposed under the outer skin layer 300, increasing hardness of the outer layer and preventing reverse curl;
a stress relief layer 500 disposed under the anti-curl layer 400, having a higher elongation and lower storage elastic modulus (G') than the outer skin layer, and relieving stress of the outer skin layer;
A UV curable deformable adhesive layer 600 disposed under the stress relief layer 500, cured by ultraviolet (UV) light, and acting as an adhesive layer while being molded to match the shape of the display surface, and having properties of a deformable material and an adhesive at the same time; and
Peeling layers 100 and 700 disposed above the anti-fingerprint reinforcement layer 200 and below the UV curable deformable adhesive layer 600 to protect them and remove during use,
The UV curable deformable adhesive layer 600 is made of a photocurable adhesive composition for window glass having a three-dimensionally curved cross section of the glass having properties of a deformable material and an adhesive at the same time,
The photocurable adhesive composition for window glass having a three-dimensionally curved cross section of the glass includes an acrylic copolymer resin having a glass transition temperature of -57 to 0 °C; A photoreactive multifunctional oligomer having a glass transition temperature of -57 to 0 ° C; And a photoinitiator; includes, and has properties of a deformable material and an adhesive at the same time,
The photoreactive multifunctional oligomer having a glass transition temperature of -57 to 0 ° C is a polyoxyalkylene block-containing photoreactive bifunctional oligomer,
Characterized in that the polyoxyalkylene block-containing photoreactive bifunctional oligomer is polyethylene glycol (PEG)-modified acrylate of Formula 1 or polypropelene glycol (PPG)-modified acrylate of Formula 2,
A protective film for window glass in which the cross section of the glass is curved in three dimensions.

[Formula 1]


[Formula 2]


(In Formula 1 and Formula 2, X is hydrogen, halogen, C1 ~ C16 alkyl or C1 ~ C20 aryl, n is a number from 200 to 1000)
According to claim 1,
The outer skin layer 300 comprises at least one synthetic resin film selected from the group consisting of polyethylene terephthalate (PET), polypropylene (PP), non-stretched polypropylene (CPP), polyurethane (PU), and polyolefin (PO) Characterized in that it comprises,
A protective film for window glass in which the cross section of the glass is curved in three dimensions.
According to claim 1,
Characterized in that the thickness of the skin layer 300 is 15 μm to 100 μm,
The cross section of the glass is a three-dimensionally curved shape. Protective film for window glass.
According to claim 1,
The anti-fingerprint reinforcement layer 200 is
Characterized in that it comprises at least one anti-fingerprint and surface-reinforcing resin composition selected from the group consisting of an acrylic resin composition, a urethane-based resin composition, and a silicone-based resin composition,
The cross section of the glass is a three-dimensionally curved shape. Protective film for window glass.
According to claim 1,
Characterized in that the thickness of the anti-fingerprint reinforcement layer 200 is 1 μm to 20 μm,
The cross section of the glass is a three-dimensionally curved shape. Protective film for window glass.
delete According to claim 1,
Characterized in that the thickness of the anti-curl layer 400 is 10 μm to 40 μm,
The cross section of the glass is a three-dimensionally curved shape. Protective film for window glass.
According to claim 1,
The stress relieving layer 500 is
Characterized in that it is made of a stress relief composition containing thermosetting acrylic or thermoplastic polyurethane (TPU),
The cross section of the glass is a three-dimensionally curved shape. Protective film for window glass.
According to claim 1,
Characterized in that the thickness of the stress relief layer 500 is 20 μm to 60 μm,
The cross section of the glass is a three-dimensionally curved shape. Protective film for window glass.
delete According to claim 1,
Characterized in that the thickness of the UV curable deformable adhesive layer 600 is 20 μm to 60 μm,
The cross section of the glass is a three-dimensionally curved shape. Protective film for window glass.
delete According to claim 1,
The photocurable adhesive composition for window glass having a three-dimensionally curved cross section of the glass is
Regarding 100 parts by weight of an acrylic copolymer resin having a glass transition temperature of -57 to 0 ° C
2.8 parts by weight to 8.3 parts by weight of a photoreactive multifunctional oligomer having a glass transition temperature of -57 to 0 °C; and
Photoinitiator 0.1 parts by weight to 7 parts by weight; containing,
The cross section of the glass is a three-dimensionally curved shape. Protective film for window glass.
According to claim 1,
The acrylic copolymer resin having a glass transition temperature of -57 ~ 0 ℃ is 2-ethylhexylacrylate (2-Ethylhexylacrylate), n-butylacrylate (n-Butylacrylate), 2-hydroxymethacrylate (2-hydroxymethacrylate), and n-dimethylacrylamide (n-Dimethylacrylamide) Characterized in that the copolymer resin composed of at least one acrylic compound selected from the group consisting of
A protective film for window glass in which the cross section of the glass is curved in three dimensions.
delete delete According to claim 1,
The exfoliation layer 100, 700 is
Characterized in that it is a silicone release film,
The cross section of the glass is a three-dimensionally curved shape. Protective film for window glass.
An acrylic copolymer resin having a glass transition temperature of -57 to 0 °C; A photoreactive multifunctional oligomer having a glass transition temperature of -57 to 0 ° C; And a photoinitiator; includes, and has properties of a deformable material and an adhesive at the same time,
The photoreactive multifunctional oligomer having a glass transition temperature of -57 to 0 ° C is a polyoxyalkylene block-containing photoreactive bifunctional oligomer,
Characterized in that the polyoxyalkylene block-containing photoreactive bifunctional oligomer is polyethylene glycol (PEG)-modified acrylate of Formula 1 or polypropelene glycol (PPG)-modified acrylate of Formula 2,
A photocurable adhesive composition for window glass having a three-dimensionally curved cross section.

[Formula 1]


[Formula 2]


(In Formula 1 and Formula 2, X is hydrogen, halogen, C1 ~ C16 alkyl or C1 ~ C20 aryl, n is a number from 200 to 1000)
According to claim 18,
The acrylic copolymer resin having a glass transition temperature of -57 to 0 ° C is 2-Ethylhexylacrylate, n-Butylacrylate, 2-hydroxymethacrylate, and n-Dimethylacrylamide. For window glass having a three-dimensionally curved cross section, characterized in that it is a copolymer resin composed of at least one acrylic compound selected from the group consisting of A photocurable adhesive composition.
delete delete According to claim 18,
The photoinitiator is 2,4,6-trimethyl-benzoyl-diphenyl-diphenyl phosphine oxide (TPO), 4,4'-bis diethylamino benzophenone (4,4'-Bis (diethylamino) benzophenone), and phenylbis (2,4,6-trimethyl benzoyl) -phosphine oxide (phenylbis (2,4,6-trimethyl benzoyl) phosphine oxide) characterized in that at least one selected from the group consisting of
A photocurable adhesive composition for window glass having a three-dimensionally curved cross section.
According to claim 18,
The photocurable adhesive composition for window glass in which the cross section of the glass is curved in three dimensions is
Regarding 100 parts by weight of an acrylic copolymer resin having a region transition temperature of -57 to 0 ° C
2.8 parts by weight to 8.3 parts by weight of a photoreactive multifunctional oligomer having a glass transition temperature of -57 to 0 °C; and
Photoinitiator 0.1 parts by weight to 7 parts by weight; containing,
The cross section of the glass is a three-dimensionally curved shape. A photocurable adhesive composition for window glass.
(1) preparing a corona-treated outer skin layer 300 made of a heat-deformable synthetic resin film, which serves as a support film;
(2) An anti-fingerprint reinforcement layer 200 having an anti-fingerprint (AF) function is disposed on the corona-treated outer layer 300 to reinforce and protect the outer skin layer 200 with a micro gravure coater. Preparing a coating with a resin composition for strengthening;
(3) preparing an anti-curl layer 400 disposed under the outer skin layer 300, increasing the hardness of the outer layer and preventing reverse curl by coating an anti-curl composition with a slot die coater;
(4) a stress relief layer 500 disposed under the anti-curl layer 400, having a higher elongation and a lower storage elastic modulus (G′) than the outer skin layer, and relieving the stress of the outer skin layer 500 with a slot die coater Preparing a stress relief composition by coating;
(5) A UV curable deformable adhesive layer 600 disposed under the stress relief layer 500, cured by ultraviolet rays (UV) and molded to match the shape of the display surface, acting as an adhesive layer, and having properties of a deformable material and an adhesive at the same time, The slot die coater is a shape in which the cross section of the glass of claim 18 is three-dimensionally curved. Preparing by coating a photocurable adhesive composition for window glass; and
(6) laminating release layers (100, 700), which are respectively disposed above the anti-fingerprint reinforcement layer 200 and below the UV curable deformable adhesive layer 600 and are removed during use while protecting them, during the manufacturing process of the anti-fingerprint reinforcement layer 200 and the UV curable deformable adhesive layer 600, respectively, on the anti-fingerprint reinforcement layer 200 and below the UV curable deformable adhesive layer 600;
The cross section of the glass is a three-dimensionally curved shape. Method for manufacturing a protective film for window glass.
25. The method of claim 24,
The step of preparing the anti-fingerprint reinforcement layer 200 in step (2) by coating the anti-fingerprint and surface-reinforcing resin composition with a micro gravure coater
After coating the corona layer of the outer skin layer 300 with a micro gravure coater that coats the corona layer with a micro-layer thickness of a resin composition for anti-fingerprint and surface reinforcement,
The anti-fingerprint and surface-reinforcing resin composition is photocured or thermally cured to form an anti-fingerprint reinforcement layer 200,
Characterized in that it comprises a process of laminating the anti-fingerprint reinforcement layer 200 and the peeling layer 100
The cross section of the glass is a three-dimensionally curved shape. Method for manufacturing a protective film for window glass.
26. The method of claim 25,
The process of forming the anti-fingerprint reinforcement layer 200 by photocuring or thermally curing the anti-fingerprint and surface-reinforcing resin composition
photocuring the anti-fingerprint and surface-reinforcing resin composition at a temperature of 30 ° C to 100 ° C with a UV lamp intensity of 200 mJ to 3000 mJ; or
Characterized in that it comprises; a step of thermally curing the anti-fingerprint and surface-reinforcing resin composition at a temperature of 60 ° C to 170 ° C
The cross section of the glass is a three-dimensionally curved shape. Method for manufacturing a protective film for window glass.
25. The method of claim 24,
The step of preparing the anti-curl layer 400, which increases the hardness of the outer skin layer and prevents reverse curl in step (3), by coating the anti-curl composition with a slot die coater
After coating the opposite surface of the outer skin layer 300 on which the anti-fingerprint reinforcement layer 200 is formed, the anti-curl composition is supplied through a nozzle-shaped fine metal plate and coated with a slot die coater,
Characterized in that it comprises a step of forming an anti-curl layer 400 by thermally curing the anti-curl composition
The cross section of the glass is a three-dimensionally curved shape. Method for manufacturing a protective film for window glass.
28. The method of claim 27,
The process of forming the anti-curl layer 400 by thermally curing the anti-curl composition
Characterized in that it comprises a; step of thermally curing the anti-curl composition at a temperature of 60 ℃ to 170 ℃
The cross section of the glass is a three-dimensionally curved shape. Method for manufacturing a protective film for window glass.
25. The method of claim 24,
The step of preparing the stress relief layer 500 for relieving the stress of the outer skin layer in step (4) by coating the stress relief composition with a slot die coater
The anti-fingerprint reinforcement layer 200 is formed on the opposite surface of the outer layer 300, the anti-curl layer 400, and coated with a slot die coater for coating by supplying the stress relieving composition between nozzle-shaped fine metal plates,
characterized in that it comprises a step of photocuring or thermally curing the stress relieving composition to form a stress relieving layer (500)
The cross section of the glass is a three-dimensionally curved shape. Method for manufacturing a protective film for window glass.
The method of claim 29,
The process of photocuring or thermally curing the stress relieving composition to form the stress relieving layer 500 is
photocuring the stress-relieving composition at a temperature of 30 °C to 100 °C with a UV lamp intensity of 200 mJ to 3000 mJ; or
characterized in that it comprises a; step of thermally curing the stress relief composition at a temperature of 60 ℃ to 170 ℃
The cross section of the glass is a three-dimensionally curved shape. Method for manufacturing a protective film for window glass.
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